South Island Field is the biggest open space on Governors Island, at more than 22 acres. It’s the area that is closed to the public except for large events. This summer will be the busiest time ever for South Island Field. I was predicting that the island will break the half-million visitor mark (in 2010 it hit 443,000 visitors); now I’m thinking the attendance record will be broken before Labor Day. Here are some things happening on South Island Field. Polo is back again. According to Amy (New York’s best blogger over at Newyorkology), the Veuve Clicquot Polo Classic will be back on June 5. The last 2 years HRH…